Post-surgical adhesions are generally fibrous bands that form between tissues and organs as a result of surgery. They may be thought of as internal scar tissue that connect tissues not normally connected, or connect permanent or resorbable implants to adjacent tissue and/or organ surfaces in a manner which is detrimental to device and/or organ function, and/or internal tissue, organ, or organ system spatial arrangement. Incorporation or integration of permanent implants to a specific tissue surface or organ may be desired however.
Adhesions form as a natural part of the body's healing process after surgery in the same way that a scar forms. The term adhesion is generally applied when the scar extends from within one tissue across to another, usually across a virtual space such as the peritoneal or thoracic cavity. As part of the process, the body deposits fibrin onto injured tissues. The fibrin acts like a glue to seal the injury and builds the fledgling adhesion, said at this point to be “fibrinous.” In body cavities such as the peritoneal, pericardial and synovial cavities, a family of fibrinolytic enzymes may act to limit the extent of the initial fibrinous adhesion, and may even dissolve it. In many cases however the production or activity of these enzymes are compromised because of injury, and the fibrinous adhesion persists. If this is allowed to happen, tissue repair cells such as macrophages, fibroblasts and blood vessel cells, penetrate into the fibrinous adhesion, and lay down collagen and other matrix substances to form a permanent fibrous adhesion. While some adhesions do not cause problems, others can prevent muscle and other tissues and organs from moving freely, sometimes causing organs to become twisted or pulled from their normal positions.
Adhesions can form in the thoracic cavity, such as after cardiac surgery or related procedures. After cardiac surgery, inflammation from surgical trauma triggers adverse events. These include fluid retention, weight gain, pleural or pericardial effusions, pulmonary congestion, pericarditis, “postcardiotomy syndrome,” and new-onset atrial fibrillation (with the potential for hemodynamic compromise and stroke).1-4 In addition, the length of hospitalization as well as the utilization of medical resources may be increased (such as the need for pleural effusion drainage and therapy for atrial fibrillation), and patients are at increased risk for readmission. These complications and treatments may add significantly to the cost of care. Medical therapies to prevent these complications have had only modest success.5-8 Therapies targeted to inhibit adhesions and the inflammatory response are needed.